A 49-year-old man has abdominal pain and experience in defecation. Which nerve allows cortical control?

The pudendal nerve is primarily responsible for providing somatic innervation to the external anal sphincter and the pelvic floor muscles, which allow for voluntary control over defecation. This control is essential for the process of bowel movements, as it enables conscious awareness and the ability to contract or relax the anal sphincter to either hold or release stool.

Cortical control of bowel functions relies on the integration of signals from the brain, mediated by the pudendal nerve, which is critical for the timing of defecation. It allows the person to decide when to initiate this process, making it central to the voluntary component of defecation. The ability to actively engage the pelvic floor muscles and sphincter provides the necessary control for social appropriateness regarding bowel habits.

Other options, such as the pelvic nerves, primarily provide autonomic, involuntary sensations that cannot be consciously controlled to the same extent. The conus medullaris refers to the end of the spinal cord, which is also not directly responsible for the cortical control of defecation. The myenteric plexus is part of the enteric nervous system and is involved in regulating the motility of the gastrointestinal tract but does not directly govern conscious control over the act of def